Miniature air compressor

ABSTRACT

A miniature air compressor includes a motor having a shaft for driving a crank. A cylinder has an open end allowing a second end of the crank extending into the cylinder for compressing the air and a close end opposite to the open end of the cylinder. The cylinder has an inlet and an outlet respectively defined in the close end thereof and extending to communicate with an inner periphery of the cylinder. A cover longitudinally mounted to the close end of the cylinder. An input passage and an output passage are respectively defined in the cover. The input passage and the output passage respectively communicate with the inlet and the outlet of the cylinder. A valve sheet secured between close end of the cylinder and the cover. The valve selectively closes the outlet in the cylinder and the input passage in the cover.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an air compressor, and moreparticularly to a miniature air compressor that can provide a stablecompressed air current.

2. Description of Related Art

A miniature air compressor usually used in art designing for providingcompressed air to an air gun for equally spraying paint. However, almostall the conventional small compressor has a complicated structure andhas a piston that may not be smoothly operated and provides an unstablecompressed air current.

The present invention has arisen to mitigate and/or obviate thedisadvantages of the miniature air compressor.

SUMMARY OF THE INVENTION

The main objective of the present invention is to provide an improvedminiature air compressor that can provide a stable compressed aircurrent.

To achieve the objective, the miniature air compressor in accordancewith the present invention comprises a motor having a shaft for drivinga crank. A cylinder has an open end allowing a second end of the crankextending into the cylinder for compressing the air and a close endopposite to the open end of the cylinder. The cylinder has an inlet andan outlet respectively defined in the close end thereof and extending tocommunicate with an inner periphery of the cylinder. A coverlongitudinally mounted to the close end of the cylinder. An inputpassage and an output passage are respectively defined in the cover. Theinput passage and the output passage respectively communicate with theinlet and the outlet of the cylinder. A valve sheet secured between theclose end of the cylinder and the cover. The valve selectively closesthe outlet in the cylinder and the input passage in the cover.

Further benefits and advantages of the present invention will becomeapparent after a careful reading of the detailed description withappropriate reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a miniature air compressor in accordancewith the present invention;

FIG. 2 is an exploded perspective view of the miniature air compressorin FIG. 1;

FIG. 3 is a partially enlarged perspective view in FIG. 2;

FIG. 4 is an operational plan view of the miniature air compressor inFIG. 1 for showing the air flowing into a cylinder of the presentinvention; and

FIG. 5 is an operational plan view of the miniature air compressor inFIG. 1 for showing the air in the cylinder being compressed andoutputted.

DETAILED DESCRIPTION OF THE INVENTION

Referring to the drawings and initially to FIGS. 1-3, a miniature aircompressor in accordance with the present invention comprises a motor(10), a transmission device (20) pivotally connected to the motor (10),a bracket (30) securely mounted to the motor (10), a cylinder (40)secured on the bracket (30) and a cover (50) longitudinally mounted tothe cylinder (40).

The motor (10) includes a shaft (11) longitudinally extending therefrom.A base member (16) is provided to support the motor (10) and multipleabsorbers (15) are mounted between the base member (16) and the motor(10) for absorbing the vibration and reducing the noise from the motor(10).

The transmission device (20) includes a connector (22) eccentrically andsecurely mounted to a free end of the shaft (11). The connector (22)includes a stub (23) perpendicularly extending therefrom opposite to theshaft (11) of the motor (10). A crank (25) is pivotally mounted to thestub (23) and is perpendicular relative to the shaft (11). The crank(25) includes a first end and a second end opposite to each other. Abearing (26) is mounted in the first end of the crank (25) and the stub(23) of the connector (22) is securely received in the bearing (26). Aresilient valve (27) is longitudinally secured on the second end of thecrank (25) by a fastener (28) and reciprocally in the cylinder (40) forcompressed air in the cylinder (40).

The bracket (30) includes a through hole (31) defined therein for thecylinder (40) laterally extending through the bracket (30).

The cylinder (40) has an open end allowing the second end of the crank(25) extending into the cylinder (40) and a close end facing the cover(50). An outlet (42) and an inlet (43) are respectively defined in theclose end of the cylinder (40) and each extending to communicate with aninner periphery of the cylinder (40). A first inclined stopper (41)extends from the close end, into the inlet (43) and facing the cover(50). A valve sheet (44) abuts an outer periphery of the cylinder (40)for covering the inlet (43) and the outlet (42). The valve sheet (44)includes a first valve (46) and a second calve (45) respectivelycorresponding to the inlet (43) and the outlet (42). The first valve(46) selectively wiggled into the inlet (43) and abuts the firstinclined stopper (41) to prevent the first valve (46) from being overlywiggled, and the second valve (45) selectively closes the outlet (42)when the crank (25) backward moved relative to the close end of thecylinder (40).

The cover (50) is securely and airtightly mounted to the close end ofthe cylinder (40) for holding the valve sheet (44) in place. The cover(50) includes an inlet passage (53) defined therein and corresponding tothe first valve (46), and an outlet passage (52) defined in the cover(50) and corresponding to the second valve (45). The first valve (46)selectively closes the inlet passage (53) when the crank (25) is movedtoward the cover (50). A second inclined stopper (51) extending from thecover (50) into the outlet passage (52). The second valve (45) iswiggled into the outlet passage (52) in the cover (50) to open theoutlet (42) in the close end of the cylinder (40) and abuts the secondinclined stopper (51) to prevent the second valve (45) from being overlywiggled in the outlet passage (52) when the crank (25) moved toward thecover (50). The cover (50) includes an input joint (54) and an outletjoint (55) laterally extending therefrom. The input joint (54) and theoutput joint (55) are respectively connected to a hose (not numbered)for easily operating the miniature air compressor in accordance with thepresent invention.

To operate the miniature air compressor of the present invention, theshaft (11) is rotated to drive the connector (22) and the crank (25) tomake the second end and the resilient valve (27) reciprocally moved inthe cylinder (40) for compressing the air in the cylinder (40). Withreference to FIG. 4, when the second end of the crank (25) beingbackward moved relative to the close end of the cylinder (40), the firstvalve (46) is wiggled into the inlet (43) in the close end of thecylinder (40) so that the input passage (53) communicates with thecylinder (40) via the inlet (43), and the second valve (45) is securelyabut the close end of the cylinder (40) to close the outlet (42) so thatthe compressed air should not flow back to the cylinder (40).Consequently, the air is sucked into the cylinder (40). With referenceto FIG. 5, when the second end of the crank (25) being moved toward theclose end of the cylinder (40), the first valve (46) securely abut thecover (50) to close the input passage (53) in the cover (50) and thesecond valve (45) is wiggled into the output passage (52) to open theoutlet (42) in the close end of the cylinder (40). Consequently, thecompressed air is outputted via the outlet (42) in the close end of thecylinder (40), the output passage (52) in the cover (50) and the outputjoint (55) of the cover (50).

Although the invention has been explained in relation to its preferredembodiment, it is to be understood that many other possiblemodifications and variations can be made without departing from thespirit and scope of the invention as hereinafter claimed.

1. A miniature air compressor comprising: a motor having a shaftlongitudinally extending therefrom; a transmission device pivotallyconnected to the shaft of the motor, the transmission device including aconnector eccentrically securely mounted to a free end of the shaft anda crank having a first end pivotally connected to the connector and asecond end opposite to the first end of the crank; a bracket securelymounted to the motor and having a through hole defined therein; acylinder extending through the through hole in the bracket and securedon the bracket, the cylinder having an open end allowing the second endof the crank extending into the cylinder for compressing the air in thecylinder and a close end opposite to the open end of the cylinder, thecylinder having an inlet and an outlet respectively defined in the closeend thereof and extending to communicate with an inner periphery of thecylinder; a cover longitudinally mounted to the close end of thecylinder, an input passage and an output passage respectively defined inand extending through the cover, the input passage communicating withthe inlet in the close end of the cylinder and the output passagecommunicating with the outlet in the close end of the cylinder; and avalve sheet secured between close end of the cylinder and the cover, thevalve sheet including a first valve selectively closing the inputpassage when the second end of the crank is moved toward the cover and asecond valve selectively closing the outlet in the close end of thecylinder when the second end of the crank is moved away from the closeend of the cylinder.
 2. The miniature air compressor as claimed in claim1 further comprising a base member for supporting the motor and multipleabsorbers mounted between the base member and the motor for absorbingthe vibration and reducing the noise from the motor.
 3. The miniatureair compressor as claimed in claim 1, wherein the crank comprises aresilient valve longitudinally secured on the second end of the crank bya fastener.
 4. The miniature air compressor as claimed in claim 1,wherein the cylinder comprises a first inclined stopped extendingtherefrom into the inlet to prevent the first valve of the valve sheetfrom overly wiggled in the inlet when the second end of the crank ismoved away from the close end of the cylinder.
 5. The miniature aircompressor as claimed in claim 1, wherein the cover comprises a secondinclined stopper extending therefrom into the output passage in thecover to prevent the second valve of the valve sheet from overly wiggledin the output passage in the cover when the second of the crank is movedtoward the close end of the cylinder.